Pros: Better visibility in video games. Higher Contrast, and lower fatigue on your eyes.
Cons: Only con would be that the pair I have give a yellow tint. Gunnar offers Crystalline lenses, which are clear with no tint!
I personally played in the professional scene in e-Sports and was fairly skeptical about these glasses. Never bothered to grab a pair as I had been wearing glasses all my life already, and another pair of glasses to wear just gaming was not worth it at the time. After switching to contacts recently I had noticed my eyes were quickly fatigued and dried out, due to the lack of blinking when gaming.
After playing with these Gunnar Glasses immediately noticed that players were much more noticeable, and colors in general were much more distinctive. For anyone who has played Counter Strike Global Offensive, you'll know that players blend into the environment very well. Not the case with these Gunnar glasses though.
For anyone who is serious about gaming and is trying to get the extra edge on other players, I definitely feel like this is a must if its in your budget!